PPM1K and obesity due to melanocortin 4 receptor deficiency: High fructose diets induce insulin resistance (Basciano et al., 2005), and reduced PP2Cm is consistent with reduced BCKDH activity seen in insulin resistant states like diabetes, as discussed later in Section “Type 2 Diabetes/Obesity.” The fact that substrate availability and insulin resistant regulate PP2Cm expression are consistent with what one might expect.